From New Scientist magazine: (about hydroelectric power)
"MP Robert Key said he had visited the Rance esturary between Dinaard and St. Malo in France the prrevious week, and praised the barrage there which has been operating reliably for more than 20 years."

barrage 2
n.
5Fr < barrer, to stop < barre, BAR16 a man-made barrier in a stream, river, etc. to deepen the water or channel it for irrigation; dam